I have had alot of success with the mechanic in a bottle and the fuel test swabs. Everytime a tool comes through our doors for repair and it runs on fuel, the first thing I do is grab the test swabs and test the fuel. It really gives me a good starting point for the repair to know if the fuel is good or not. If I have a hart time starting the tool and the fuel is good i reach for the machanic in a bottle. It makes it nice to not have to tear a carb apart everytime. The Machanic in a bottle does save me a lot of time and hassle. The ethanol shield is the tool that I give The customers when they come back to pick up their tools. After I explain to the customer that using this product will keep them from repairing their tools so often. It is a really good selling point for the customer and they really like the ethanol shield.